Sectional gears



H. Y. LEE

SECTIONAL GEARS I Nov. 11, 1958 a w? 5 05 .f w R E 5222 2.24. l w N Z I.i m fi 2 .N, "H 2 .m A E F F w M 3 I 2 m m 2 2N0? 2 4 M 9 m m m m m.

Un ed ates Pa SECTIONAL GEARS Henry Y. Lee, Honolulu, Territory ofHawaii Original application April 9, 1953, Serial No. 347,711,

now Patent No. 2,748,618. Divided and this application March 14, 1956,Serial No. 571,431

2 Claims. (Cl. 74- 439) This invention relates to sectional gears, andmore particularly to sectional gears which are divided transversely oftheir axes of rotation and comprising a pair of aligned and peripherallytoothed elements, the present application being a division of my pendingpatent application Serial No. 347,711, flied April 9, 1953, now PatentNo. 2,748,618.

As stated in the aforementioned pending patent application, it iswell-known that the subjection of .gears of all types to repeated forcesof bending, pressure and friction results in gradual wear on the gearteeth and fatigue of the metal of which they are composed, therebyrequiring frequent repair or replacement. This is particularly true ofperipherally toothed gears.

In the case ofherringbone gears, both their production and rep-air areconsiderably more difficult and require a more specialized type of skilland equipment than for such gears as spur, bevel, spiral, etc.

It is among the objects of the present invention, as well as that of theaforementioned earlier patent application, to substantially reduce thedisadvantages set forth hereinabove by providing a sectional gearstructure which is comparatively inexpensive and easy to manufacture,and yet efficient and durable in service.

Another object is the attainment of the foregoing objectives with asectional gear which may be easily and speedily repaired or replaced.

Still another object is to provide a peripherally toothed gear of theherringbone type which is possessed of the foregoing characteristics.

A further object is to provide an improved gear of the type referred towhich is characterized by improved distribution of the load from thefastening instrumentalities.

A still further object is the provision in a gear of the class describedof means enabling certain of the component parts to be made from stocksof standard shape and of diiferent metals as determined by the use forwhich they are intended.

The invention, then, comprises the features fully described, and asparticularly pointed out in the claims, the following description andannexed drawings setting forth in detail illustrative embodiments of theinvention, these being indicative of but several of a number of ways inwhich the principles of the invention may be employed.

In said drawings:

Figure 1 is a side elevational view of a gear of the so-called web typewhich embodies the teachings of the present invention;

Figure 2 is a sectional view on the line 2-2 of Figure 1;

Figure 3 is a side elevational view of a modification, the samecomprising a pug nose herringbone gear which utilizes a hub and web; and

Figure 4 is a sectional view on the line 33 of Figure 3.

Referring more particularly to the drawings, the sec- 2 tional gear ofFigures 1 and 2 comprises a left-hand gear section and a right-hand gearsection, the said sections being divided or split transversely of theiraxes of rotation and adapted for closely abutting relationship. Theperipheries of these gear sections, which will be described more fullyhereinafter, are provided with oblique or helical teeth' 12 of identicalshape and size; whereby the said sections may be so assembled as to formthe composite V-shapedteeth which characterize .a herringbone gear.

' The gear of Figures 1 and 2 comprises a conventional ,hub with a web19 having a machine-finished circumferential rim 20 (see Figure 2) whichoccupies correspondingly shaped opposed recesses H in the left-hand andright-hand gear bands 22 and 23, respectively.

Referring still to Figure 2, each of the opposed recesses 21 (-in theleft-hand and right-hand gear bands 22 and 23, respectively) is of adepth sufficient to accommodate one-half of the thickness of themachinefinished circumferential rim 20, whereby the latter is fullyencased. Each of the left-hand and right-hand gear bands 22 and 23 isprovided with a flange 24 which extends inwardly of, and perpendicularlywith respect to, the toothed periphery of each gear band, the saidflanges forming extensions of the inner faces of the aforementionedopposed recesses 21. According to such construction, the gear bands 22and 23 may be bonded together, and to the machine-finishedcircumferential rim 20 of the web 19, by means of bolts 25 andlocked-nuts 26, the said bolts extending through anchor holes 27 in theaforementioned flanges 24 and anchor holes 28 in said rim 20.

Setting or identification of the gear teeth may be made on the exteriorcheeks of the toothed elements by means of punched markings 29 (seeFigure 1) in the manner well known in the art.

In view of the fact that the maximum force exerted on the teeth ofherringbone gears is at the junction of the helical teeth, it is at suchpoints that repair is most frequently required; and one of the mostimportant objectives of the present invention is to provide a sectionalgear which is analogous to the gears of Figures 1 and 2, but which ischaracterized by increased strength at the mid-section of the toothedperipheries of the gear components. Such increased strength accrues fromthe pugnose herringbone gear shown in Figures 3 and 4.

The pug-nose herringbone gear of Figures 3 and 4 comprises a web 44carried by a hub 45, the periphery of the web being provided with teeth46 of the spur gear type. The numerals 47 and 48, respectively,designate the left-hand and right-hand gear bands, the peripheries ofwhich are provided with oblique or helical gear teeth 49. The outsidediameter, pitch diameter and number of teeth 49 on the gear bands 47 and48 are the same as those of the spur teeth 46 of the web 44; and therespective teeth are, of course, aligned to form a pugnose herringbone.

As shown in Figure 4, each of the left-hand and righthand gear bands 47and 48 is provided with a flange 50 which extends inwardly of, and atright-angles to, the toothed peripheries of said gear bands. Theseflanges 50 form extensions of the inner faces of the gear bands andpermit all three of the toothed gear elements or sections to be securedor bonded together by bolts 51 and locked-nuts 52, the bolts 51extending through aligned anchor holes 53 in the web 44 and the flanges50 on either side thereof.

As in the case of the embodiment of Figures 1 and 2, punch markings 54on the exposed surfaces of the gear bands 47 and 48 and the intermediateweb 44 may be used to identify, match, or time the various gearelements.

While I have shown and described certain specific embodiments of thepresent invention, it Will be readily understood by those skilled in theart that I do not Wish to be limited exactly thereto, since variousmodifications may be made Without departing from the scope of theinvention as defined in the appended claims.

I claim':

1. A sectional gear comprising a hub, a radial flange carried by saidhub, the periphery of said flange being provided with gear teeth, a pairof similar and cooperative centrally apertured gear elements which areso disposed that the adjacent'ends of their respective teeth closelyabut and are in alignment with the gear teeth on provided with gearteeth, a pair of similar and cooperative centrally apertured gearelements which are so disposed that the adjacent ends of theirrespective teeth closely abut and are in alignment with the gear teethon the periphery of said radial flange, a flange carried by each of saidgear elements, said last-mentioned flanges extending radially inwardtoward said rotatable hub with the inner ends thereof in contact withthe annular shoulders on the sides of said first-mentioned radialflange, and screw-threaded means for holding all of said flangestogether.

References Cited in the file of this patent UNITED STATES PATENTS332,998 Coupland Dec. 22, 1885 415,044 Ioslin Nov. 12, 1889 470,952Seholfield Mar. 15, 1892 1,165,830 Alquist Dec. 28, 1915 1,512,560 MooreOct. 21, 1924 Lee June 5, 1956

